1. Field of the Invention
This invention relates to fatty acid polyoxyalkyl ester sulfonates obtained by reaction of C.sub.11 -C.sub.22 monounsaturated monocarboxylic acid polyoxyalkyl esters with sulfur trioxide and subsequent reaction of the sulfonated fatty acid polyoxyalkyl ester obtained with aqueous alkali metal salts.
2. Discussion of Related Art
Commercially the most important anionic surfactants are those which contain a sulfone group as a water-solubilizing group. Such surfactants may be divided into sulfate surfactants and sulfonate surfactants.
Sulfate surfactants are semiester salts of sulfuric acid. The most important representatives of this subgroup are the alkyl ether sulfates which, by virtue of their glycol ether groups, are readily soluble in water and are therefore particularly suitable for use in the production of liquid detergents and cleaning preparations. One disadvantage of these compounds, however, is their poor hydrolysis stability so that they cannot be used for acidic cleaning preparations.
Sulfonate surfactants include the salts of alkylsulfonic acids which are stable to hydrolysis, even in acidic medium. Sulfonate surfactants which contain glycol ether groups to improve their solubility in water include the alkyl glycol ether sulfonates known from U.S. Pat. 1,985,747, the alkyl glyceryl ether sulfonates known from German Patents 1,075,779 and 1,081,172 and the fatty alkyl (polyoxyalkyl) lower alkyl ether sulfonates known from German Patent 33 31 513.